A multi-pronged attack designed to unravel the complexities of prostaglandin pharmacology and physiology in mammals since the intelligent use of PG's in clinical situations is hampered by 1) our incomplete understanding of their physiological role 2) the wide spectrum of pharmacological responses elicited, and 3) the lack of rapid clinical assays for the prostaglandin system components. The proposed research includes conformational studies of the PG's, their diastereomers, and specific analogs in connection with detailed structure-activity and receptor modeling. The studies of solution conformation, using circular dichroism and lanthanide NMR effects in aqueous and mixed aqueous-organic media, will then be extended to the thromboxanes and PGX and to fatty acids, particularly the poly-unsaturated groups. Analogs of thromboxane B1, A2, and B2 will be synthesized, and similarly evaluated both as to conformation and pharmacology. The other objectives of the research are essentially tools for delineating the control of prostaglandins in vivo. Prostaglandin metabolizing enzymes will be isolated by affinity chromatography and studied as to specificity of action. The enzymes isolated in combination with radiolabeled agarose-tethered prostaglandin substrates, will be used for rapid microscale assays of prostaglandins. The radiolabeled agarose-tethered prostaglandins will also be the basis for assays for PG metabolizing enzyme levels. Polymer tethering, using water soluble polymers, of natural PG's should produce agonists that distinguish between physiological effects that require cell membrane penetration and those resulting from an outside receptor interaction.